Forces (terminal velocity, moments, elasticity) Flashcards
What do resultant forces cause (2)
Change in shape
Change in their motion
What does an object that is not changing motion or shape experience
No resultant force
What are forces so what do they have
Vectors, so have a magnitude (size e.g. 10 newtons) and a direction
What are scalers
Not vectors, they are quantities that only have a magnitude e.g. length, area, mass, time
What must you look at to find the resultant force
Size and direction
What is Newton’s first law
If the resultant force acts on an object then that object will accelerate
So if there are a number of forces on an object but the resultant force is 0N then there will be no change in motion
What is Newton’s second law
Resultant force = mass x acceleration
F = m x a
What happens if the resultant force is in the direction of motion in an object
It will accelerate
What happens if the resultant force is opposing the motion of an object
It will decelerate
What does friction oppose
Motion
What is the equation that links gravitational pull, weight and mass
w = m x g
What is terminal velocity
The maximum constant speed of an object as the resistance is preventing it from accelerating any further
How does an object reach its terminal velocity
As an object falls it accelerates
As the object falls and gets faster the resistive force increases
Acceleration starts to decrease as the resultant force is getting less
At a certain speed the resistance and the weight will eventually be equal so the forces are balanced and the object is no longer accelerating
The object continues to fall but at a constant speed which is called its terminal velocity
How can we increase the terminal velocity
Make the object more aerodynamic or streamlined so resistance is reduced
What is a moment
It is the turning effect caused by a force